<template>
  <div>
    <section class="msite">
      <!--首页头部-->
      <HeaderTop :title="address.name">
        <router-link class="header_search" slot="left" to="/search">
          <i class="iconfont icon-sousuo"></i>
        </router-link>
        <router-link class="header_login" slot="right" :to="userInfo._id ? '/userinfo': '/login'">
        <span class="header_login_text" v-if="!userInfo._id">
          登录|注册
        </span>
          <span class="header_login_text" v-else>
           <i class="iconfont icon-person"></i>
        </span>
        </router-link>
      </HeaderTop>
      <div class="miste-content-wrapper">
        <div class="miste-content">
          <!--首页导航-->
          <nav class="msite_nav">
            <div class="swiper-container" v-if="categorys.length">
              <div class="swiper-wrapper">
                <div class="swiper-slide" v-for="(categorys, index) in categorysArr" :key="index">
                  <a href="javascript:" class="link_to_food" v-for="(category,index) in categorys" :key="index">

                    <div class="food_container">
                      <img :src="baseImageUrl+category.image_url">
                    </div>
                    <span>{{ category.title }}</span>
                  </a>

                </div>
              </div>
              <!-- Add Pagination -->
              <div class="swiper-pagination"></div>
            </div>
            <img src="./images/msite_back.svg" alt="back" v-else>
          </nav>
          <!--首页附近商家-->
          <div class="msite_shop_list">
            <div class="shop_header">
              <i class="iconfont icon-xuanxiang"></i>
              <span class="shop_header_title">附近商家</span>
            </div>
            <ShopList/>
          </div>
        </div>
      </div>
    </section>
  </div>
</template>

<script>
import {mapState} from 'vuex'
import Swiper from 'swiper'
import 'swiper/dist/css/swiper.min.css'
import HeaderTop from "../../components/HeaderTop/HeaderTop.vue";
import ShopList from "../../components/ShopList/ShopList";

export default {
  data() {
    return {
      baseImageUrl: 'https://fuss10.elemecdn.com'
    }
  },

  mounted() {
    this.$store.dispatch('getCategorys')
    this.$store.dispatch('getShops')


  },
  computed: {
    ...mapState(['address', 'categorys', 'userInfo']),
    /*
    根据categorys一维数组生成一个2维数组
    小数组中的元素个数最大是8
     */
    categorysArr() {
      const {categorys} = this
      // 准备空的2维数组
      const arr = []
      // 准备一个小数组(最大长度为8)
      let minArr = []
      // 遍历categorys
      categorys.forEach(c => {
        // 如果当前小数组已经满了, 创建一个新的
        if (minArr.length === 8) {
          minArr = []
        }
        // 如果minArr是空的, 将小数组保存到大数组中
        if (minArr.length === 0) {
          arr.push(minArr)
        }
        // 将当前分类保存到小数组中
        minArr.push(c)
      })

      return arr
    }
  },
  watch: {
    categorys(value) {//categorys数组中有数据了，在异步更新界面之前执行
      //使用setTimeout可以实现效果，但不是太好
      /*setTimeout(()=>{
        //创建一个Swiper实例对象来实现轮播
        new Swiper('.swiper-container', {
          loop: true, // 可以循环轮播
          // 如果需要分页器
          pagination: {
            el: '.swiper-pagination',
          },
        })
      },100);*/

      // 界面更新就立即创建Swiper对象
      this.$nextTick(() => {//一旦完成界面更新，立即调用
        new Swiper('.swiper-container', {
          loop: true, // 可以循环轮播
          // 如果需要分页器
          pagination: {
            el: '.swiper-pagination',
          },
        })
      });
    }
  },
  components: {
    HeaderTop,
    ShopList
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import "../../common/stylus/mixins.styl"
.msite //首页
  width 100%

  .header
    background-color #02a774
    position fixed
    z-index 100
    left 0
    top 0
    width 100%
    height 45px

    .header_search
      position absolute
      left 15px
      top 50%
      transform translateY(-50%)
      width 10%
      height 50%

      .icon-sousuo
        font-size 25px
        color #fff

    .header_title
      position absolute
      top 50%
      left 50%
      transform translate(-50%, -50%)
      width 50%
      color #fff
      text-align center

      .header_title_text
        font-size 20px
        color #fff
        display block

    .header_login
      font-size 14px
      color #fff
      position absolute
      right 15px
      top 50%
      transform translateY(-50%)

      .header_login_text
        color #fff

  .msite_nav
    bottom-border-1px(#e4e4e4)
    margin-top 45px
    height 200px
    background #fff

    .swiper-container
      width 100%
      height 100%

      .swiper-wrapper
        width 100%
        height 100%

        .swiper-slide
          display flex
          justify-content center
          align-items flex-start
          flex-wrap wrap

          .link_to_food
            width 25%

            .food_container
              display block
              width 100%
              text-align center
              padding-bottom 10px
              font-size 0

              img
                display inline-block
                width 50px
                height 50px

            span
              display block
              width 100%
              text-align center
              font-size 13px
              color #666

      .swiper-pagination
        > span.swiper-pagination-bullet-active
          background #02a774

  .msite_shop_list
    top-border-1px(#e4e4e4)
    margin-top 10px
    background #fff

    .shop_header
      padding 10px 10px 0

      .shop_icon
        margin-left 5px
        color #999

      .shop_header_title
        color #999
        font-size 14px
        line-height 20px


</style>
